FUNDAMENTAL PROPERTIES OF STARS USING ASTEROSEISMOLOGY FROM<i>KEPLER</i>AND<i>CoRoT</i>AND INTERFEROMETRY FROM THE CHARA ARRAY

Abstract

We present results of a long-baseline interferometry campaign using the PAVO\nbeam combiner at the CHARA Array to measure the angular sizes of five\nmain-sequence stars, one subgiant and four red giant stars for which solar-like\noscillations have been detected by either Kepler or CoRoT. By combining\ninterferometric angular diameters, Hipparcos parallaxes, asteroseismic\ndensities, bolometric fluxes and high-resolution spectroscopy we derive a full\nset of near model-independent fundamental properties for the sample. We first\nuse these properties to test asteroseismic scaling relations for the frequency\nof maximum power (nu_max) and the large frequency separation (Delta_nu). We\nfind excellent agreement within the observational uncertainties, and\nempirically show that simple estimates of asteroseismic radii for main-sequence\nstars are accurate to &lt;~4%. We furthermore find good agreement of our measured\neffective temperatures with spectroscopic and photometric estimates with mean\ndeviations for stars between T_eff = 4600-6200 K of -22+/-32 K (with a scatter\nof 97K) and -58+/-31 K (with a scatter of 93 K), respectively. Finally we\npresent a first comparison with evolutionary models, and find differences\nbetween observed and theoretical properties for the metal-rich main-sequence\nstar HD173701. We conclude that the constraints presented in this study will\nhave strong potential for testing stellar model physics, in particular when\ncombined with detailed modelling of individual oscillation frequencies.\n